1. Field of the Invention
The present invention relates to an improved fence or railing to be made on an industrial basis. Where it serves as a fence, the latter restricts entry into a piece of land or separates one piece of land from another. The invention may also serve as a railing fixed to a balcony or the like.
2. Description of the Prior Art
Fences or railings of the type with which the invention is concerned are both functional and ornamental; their elements being made of extruded plastic material. A fence or railing comprises two major components: the posts and the area-separation or guard sections; each section being essentially formed of a top and of a bottom rail separated by vertical struts; the ends of the rails being connected to two posts. A post, on the other end, may be an end post with only one area-separation section attached to it; a line post with two sections in alignment; a corner post with two and up to four sections successively at right angles and a plain post with no section attached and serving to hinge a gate, making a total of six different types of posts to meet all situations.
An industrial problem involved with present day fence or railing constructions, apart from the large number of different posts required, is broadly that specialized machinery must be used to prepare at least the major components: the posts and the horizontal top and bottom rails. Also, when prepared for one particular installation, the components cannot be changed or altered to meet the requirements of another installation. This condition leads to high costs in manufacturing, in repair work and in inventory.
In the case of the posts, for instance, holes are to be made through their sides at precise locations to receive the ends of the rails of the area-separating sections. A post cannot therefore be changed to fit another situation where the rails are distanced differently and/or are provided on different numbers of sides of the posts. It will be remembered, in this latter regard, that six different types of posts must presently be stored to meet all requirements, as mentioned above.
Additionally, posts now used are essentially plain square plastic hollow tubes which have to be reinforced by pouring concrete into them at least up to a certain height embedding, by the same token, the ends of the bottom rails, so that if changes have to be made to the fence or railing, involving displacement of the rails, the fence or railing has to be completely dismantled and the posts and rails irreperably damaged.
As to the rails of the area-separating sections or guard sections, two different types are used.
In one case, where they are essentially plain square plastic hollow tubes, as the posts, holes have likewise to be made into them, using specialized machinery, and the vertical struts slid directly into them. This construction provides the struts with a high degree of solidity as they are securely held, by their ends, inside the hollow rails. However, the method prevents easy modification of the strut arrangement when the assembly is completed.
To avoid this drawback, channels have been secured to one face of the rectangular rails; the struts fitting into these channels and being kept apart by spacing inserts slidably fitting into guiding slots pre-formed along the legs of the channels. This method of construction permits easy modification of the strut arrangement but the latter is substantially weaker than in the above case because if a sufficiently strong lateral pressure is applied to the struts, they will bend out, twist the rails and even pop out of the channels.
In both cases, strengthening of the rails has been attempted by inserting metal channels into them. But being unprotected from rain water, the rails tend to crack during winter as the plastic and metal expand and contract at different rates due to freezing and thawing.